Pneumatic fabric edge decurler

ABSTRACT

A PNEUMATIC DEVICE FOR FLATTENING AND DECURLING FABRIC EDGES IS DISCLOSED. THE NEW DEVICE IS IN THE FORM OF A RELATIVELY STRAIGHT AIR TUBE EXTENDING INWARD FROM A POINT OUTSIDE THE FABRIC EDGE. THE OUTLET OF THE TUBE DIRECTS AIR OUTWARDLY ALONG THE FABRIC SURFACE TOWARD ITS EDGES AND CAN BE UTILIZED IN MANY LOCATIONS IN A FABRIC PROCESSING LINE AS A SPOT DECURLER.

June l, 1971 E CQHN ETAL 3,581,356

PNEUMATIC FABRIC EDGE DECURLER Driginal Filed Jan. 25. 1967 3 Sheets-Sheet 1 l BWMJLJMMMJBP ATTORN EYS June 1, 1971 E. COHN ETAI- PNEUMATIC FABRIC EDGE DECURLER FIG. 2

3 Sheets-Sheet 2 VM' Lv 0 0; i z z ,i i. z 2 fi EL" i f i f I1 34 33 INVENTORS EUGENE COHN FRANK CATALLO 32 WMI! im@ ATTORN EYS June l, 1971 E, COHN ETAL 3,581,356

PNEUMATIC FABRIC EDGE DECURLER Original Filed Jan. 25, 1967 3 Sheets-Sheet 5 FIG 5 INVENTORS EUGENE COHN FRAN K CATALLO ATTORNEYS United Stam Patent O Int. Cl. D06c 3/00 U.S. Cl. 26--54 5 Claims ABSTRACT F THE DISCLOSURE A pneumatic device for flattening and decurling fabric edges is disclosed. The new device is in the form of a relatively straight air tube extending inward from a point outside the fabric edge. The outlet of the tube directs air outwardly along the fabric surface toward its edges and can be utilized in many locations in a fabric processing line as a spot decurler.

RELATED APPLICATION This application is a division of our copending application Ser. No. 611,609, filed I an. 25, 1967 entitled Apparatus for Distending Web Materials, now U.S. Pat. No. 3,494,011, granted Feb. 10, 1970.

BACKGROUND OF THE INVENTION Knitted fabric is particularly characterized by its geometric instability, in that it is readily distortable under tensions and other forces normally applied during fabric processing. In addition, the width and length dimensions of a knitted fabric are inherently interrelated, such that lengthwise tensions applied to the fabric during normal processing result not only in elongation of the fabric `but in a corresponding narrowing of the fabric width. When the fabric is processed in open width form, additional problems are presented, particularly with regard to stabilization of fabric geometry and to a tendency for the fabric edges to curl.

Heretofore, it has proven very difficult to process knitted fabric in open width form, because of the inability to maintain control over the geometry of the fabric (i.e., its length and width dimensions, stitch or loop formation, cross line configuration, etc.). And, it has been more customary to process the knitted fabrics in tubular form and thereafter to slit and open the processed tube. However, processing prior to slitting and opening results in an edge crease in the center of the open width fabric, which is objectionable in the finished product (e.g., often a lamination with vinyl) and is very difiicult to remove. Because the edge crease problem is obviated by processing the fabric in open width form, there has been an increasing need for processing lines and equipment suitable to this purpose.

A detailed description of a particularly advantageous processing line for open width knitted fabrics may be found in our aforementioned copending patent application, of which this application is a division. The primary objective of the present invention is to provide a spot edge decurling device of novel structure for ensuring that the edges of the open width fabric being processed are flat and uncurled at various critical stages of the processing line.

SUMMARY OF THE INVENTION In accordance with the objective of processing knitted fabric in open width form, the invention provides a new and improved device for ensuring that the edges of a knitted fabric being processed are in an uncurled condition immediately prior to entering downstream processing units such as those described in detail in our aforementioned copending application.

In accordance with the invention, the new edge decurling device includes the provision of strategically positioned spot decurling devices to cope effectively with the inherent tendency of the open width knitted fabric to curl at the edges. The spot decurlers of the invention are novel air devices, which act on the fabric locally, immediately in advance of a processing nip or other point in the processing line where curl-free fabric is required, and are effective to deliver curl-free fabric without requiring it to be mechanically manipulated.

Outwardly, the new and improved spot decurler resembles a whistle and includes an air discharge opening having the form of an inclined notch. The spot decurlers of the invention are located close to the edge portion of the advancing fabric, usually on both edges in the section of the processing line where edge curling is expected. The new devices are placed near the edge of the fabric, with the inclined notch air discharge opening positioned to direct an air flow outwardly toward the fabric edge along a surface of the fabric.

For a better understanding of the above and other features of the invention, reference should be made to the following detailed description and to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. l is an elevational view of a fabric handling and processing line incorporating the edge decurling devices of the invention;

FIGS. 2 and 3 are enlarged, fragmentary, cross-sectional and plan views, respectively, of advantageous fabric handling and guiding devices incorporated in the processing line of FIG. l;

FIGS. 4 and 5 are enlarged, fragmentary plan and elevational views, respectively, of an advantageous fabric edge decurler and edge sensing means in accordance with the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to the drawings, and initially to FIG. 1, the reference numeral 10 designates a supply container for web material to `be processed. The web material 11 most advantageously is an open width knitted fabric and will be assumed to be such in the remainder of this description. However, it will be understood that at least certain aspects of the present invention may be applicable to other web materials, including tubular knitted fabrics, as will appear.

As illustrated in FIG. l, the open width knitted fabric web 11 advantageously is guided upwardly out of the supply container 10, through a first stage fabric handling and guiding system 12 (if necessary), and over and about an idler roll 13. The guiding and handling system 12, described in our aforementioned copending application, functions to manipulate the fabric web to a substantially fiat form and serves to at least approximately center the fabric web relative to the principal longitudinal axis of the processing line.

After passing over the guide roller 13, the generally flat web of open width fabric travels downward to and around a attening roll 14 and then through a second stage fabric handling and guiding system 1S which is generally similar to the first stage handling and guiding system 12 located directly above the supply container. The handling and guiding system 15 acts upon the fabric in a manner to present it in substantially flat, wrinkle-free form and also substantially centers the fabric along the axis of the processing line.

In the processing line illustrated in FIG. 1, the spreadtiat open width knitted fabric is advantageously directed through a padding processor, generally designated by the numeral 16, the fabric having been decurled immediately in advance thereof, in accordance with the invention. The padding processor may typically consist of three processing rollers 17-19, arranged to form a reservoir 20 for the processing liquid, a first nip 21 for extracting the fabric (if necessary) and a processing nip 22 for padding the processing liquid.

The fabric discharged from the exit side nip 22 of the processing pad 16 is guided to a distending or spreading apparatus generally designated by the numeral 26 which serves to laterally distend the impregnated fabric to a predetermined, uniform width.

After lateral distension to a predetermined width, the fabric, now designated by the numeral 2.7, is discharged over a control roller 28 and guided about an input speed roller 29 for a fabric drying and/or curing apparatus generally designated by the numeral 30.

As shown particularly in FIGS. 2 and 3, the fabric advantageously is directed through a plurality of manipulating steps, subsequent to the second air guide stage 15, in order to assure presentation of the fabric to the processing pad in a fiat, wrinkleand curl-free condition. To this end, the fabric 11 being advanced from the second handling stage is passed over and under flattening bars 31, 31a. respectively which extend across the full width of the equipment and are so positioned relative to the path of travel of the fabric as to lighty engage the bottom and top surfaces of the fabric, applying a very light tension thereto.

After passing through the flattening bars 31, 31a, the fabric is directed upwardly over a series of air jet tubes 33-35 in accordance with the invention and around bar 32. The air jet tubes 33-35, which are aptly described as whistle jets" because of their appearance, are adjustably disposed at each side of the equipment in cooperative relation to the opposite edge margins of the fabric. A suitable guide plate 36 extends in the plane of the air jet tubes, arranged so that the fabric is guided over the tops of the tubes. As shown in FIG. 3, the air jet tubes 33-35 are provided with air outlet openings arranged to direct relatively high velocity and confined streams of air transversely outward toward the edge extremities of the fabric. The illustrated arrangement contemplates that the fabric presented to the jet tubes 253- will be so oriented that its tendency to curl is toward the bottom. Accordingly, the jet tubes are arranged to direct high velocity air streams transversely outward along the bottom surface of the fabric to remove any curl which tends to form.

As shown in FIGS. 4 and 5, the new fabric flattening and decurling device preferably includes a fabric edge sensing assembly 37 which may be substantially identical at each side. The unit 37 may comprise (for example) a pair of closely spaced, vertically oriented light sources 38, 39 and a corresponding pair of photocell receptors 40, 41 aligned therewith. The light sources and photocell receptors may be relatively closely spaced (e.g., about one-half inch separation), to provide for a reasonably small maximum edge variation tolerance. But advantageously, the light and receptor pairs are mounted in rotatably adjustable platforms 42, 43, to enable the tolerance to be varied from the maximum to any smaller tolerance by appropriate rotational orientation of the pairs. Each of the pairs of edge sensors 37 is connected through appropriate electrical control facilities (not shown, but conventional) to respective motors which respond to wandering of the fabric edge to maintain the edge sensors over the fabric edge. Suitable means for readjusting the position of the edge sensor assembly 37 are known in the electrical control arts and do not form a part of the invention.

In accordance with the invention and in conjunction with each of the pairs of edge sensing elements, there is provided a whistle jet tube 44 arranged to direct a decurling stream of air transversely outward, to make certain that the fabric is in its fully flat condition and free of curl at the instant of edge sensing. As shown best in FIG. 5, the whistle jet tube 44 comprises an air tube 45 closed at one end by a cap 46 and having an air inlet opening at the other end. Near the capped end, there is provided a notched air discharge opening 47 in the form of an inclined notch, which typically is straight, across the outer or capped end, and tapers out to the air tube wall at the inner end. Received within the air tube and spanning the opening 47 is a plug 48 provided with an axial air passage 49 and a partial recess 50 disposed along one side, opposite the opening 47 and inclined to correspond generally with the outlines of the opening. The plug and recess extend inward, well beyond the discharge opening, as shown.. The arrangement is such that air entering from the inlet end of the tube 45 is required to tiow through the plug passage 49 and then reverse direction. The reversely flowing air travels through the recess 50, along a portion of the inner wall of the air tube 45, and is discharged at relatively high velocity out of the whistle opening 47. The advantageous How pattern of the air is such that it is confined along the outside wall of the tube 45 and directed generally back toward the air inlet end.

The whistle jet is a very simplified, yet highly effective arrangement, suitable for mounting outside the fabric edges, for effecting decurling of the fabric edges. Because of the compact configuration of the jets, they may be located extremely close to critical processing points, for spot decurling at the last instant prior to processing.

It is to be understood, of course, that the device herein illustrated and described is intended to be representative only, as certain changes may be made therein without departing from the clear teachings of the disclosure. Accordingly, reference should be made to the following appended claims in determining the full scope of the invention.

We claim:

l. A fabric guiding and edge decurling device comprising (a) a relatively straight-walled air tube having an outlet portion disposed adjacent an edge extremity of the fabric and an inlet portion located outward of the outlet, relative to the center of the fabric,

(b) said outlet portion having an air discharge opening directed outwardly toward the edge extremity of the fabric,

(c) said air discharge opening being generally in the form of an outwardly inclined notch in the wall of the tube, and

(d) fiow passage means within said outlet portion of the air tube permitting passage of the air flow therethrough past the air discharge opening, directing the air flow outwardly and confining the air flow closely adjacent the tube wall as it approaches the discharge outlet.

2. The device of claim 1, wherein (a) said flow passage means includes a plug positioned in the inner end portion of the tube opposite the discharge opening.

3. The device of claim 1, further including (a) fabric edge sensing means, and

(b) means for controlling the position of the fabric edges, in response to the position of the fabric edge as determined by said sensing means,

(c) said air tube being positioned closely adjacent said sensing means to maintain flat edge conditions in the immediate region of the sensing means.

4. The device of claim 3, wherein (a) said fabic edge sensing means includes a pair of vertically oriented light sources and a corresponding pair of photocell receptors aligned therewith.

5 5. A spot decurling device for handling open width knitted fabrics and the like, comprising (a) an air tube having an outlet portion disposed adjacent an edge extremity of the fabric,

`(b) said outlet portion having an air discharge opening formed therein in a form to direct discharged air generally longitudinally of the outlet portion of the air tube and toward the edge extremity of the fabric,

(c) said discharge opening being generally in the form of an inclined notch,

(d) ow passage means being provided within the outlet portion of the air tube to cause the air ow to be confined closely adjacent the tube wall as it appreaches the discharge outlet,

(e) said air tube being a relatively straight tube and 15 having an inlet portion located outside of the outlet portion, relative to the center of the fabric, (f) said ow passage means comprising a plug in the tube, positioned opposite the discharge opening, and (g) said plug having an axial passage for outward-toinward flow of incoming air and a partial recess on one side, directly opposite the discharge opening and extending inward thereof, for confining inward-tooutward air low toward said discharge opening.

References Cited UNITED STATES PATENTS 994,780 6/1911 Olney 239-590 1,676,035 7/1928 Lehnert 239-590 1,912,724 6/1933 Remington 28-1(E)(UX) 1,978,721 10/1934 Perkins 239-590(X) 2,674,023 4/1954 Foley 28-1(E)(UX) 3,142,107 7/1964 Wittig 26-54 3,414,991 12/1968 Oelkers et al. 38-143(X) FOREIGN PATENTS 934,955 8/1963 Great Britain 28-1(E) 937,512 9/1963 Great Britain 28-1(E) ROBERT R. MACKEY, Primary Examiner 20 U.S. C1. X.R. 38-143; 239-590 

